means Malt malted barley. The vast
majority of the grain that is malted is
barley. Malt has brewing, distilling,
baking and confectionary uses.
Malt
Other grains (mainly wheat and rye)
can also be malted. In those cases
the products are referred to as wheat
malt or rye malt. Mostly those are
used in some specialty beers and
distilling.
Barley is a small grain, with appearance
similar to wheat and rye. It has distinct
awns (whiskers).
Barley
grain
head
small grain seed heads
oats
barley
wheat
rye
Barley cultivars are classied as
two-row or six-row depending on the
arrangement of kernels in the grain
head viewed from the end.
barley eld
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Two-row barley seeds tend to be
plumper and contain more extract
(mainly starch) per unit weight than
six-row barley.
Six-row barley, on the other hand, has
a higher content of protein and
enzymes per unit weight.
2-row barley
6-row barley
Feed Barley vs. Malting Barley
Only certain barley cultivars (varieties)
are approved for malting.
Even barley of these cultivars must meet
certain specications. Malting barley that
meets specications commands a
premium price.
2-row barley
6-row barley
Barley has a huge agronomic range. It
can be grown from the Equator to the
Arctic Circle.
Barley that is not acceptable for malting
is mainly used for human or animal food.
U.S. Malting Barley Production
Malting barley is typically a bit more
circumscribed but it is grown in
Australia*, Canada*, China, France*,
Germany, Japan, Russia, Scandinavia,
South Africa, United Kingdom, and the
US among other places.
*major exporters (as malt)
2-row malting barley
6-row malting barley
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Dormancy
The Malting Process
Immediately after harvest, seeds are
unable to grow. This prevents their
sprouting at the wrong time of year
and is called dormancy.
Steeping
Germination
As time passes, seeds lose their
dormancy and become capable of
sprouting.
Kilning
The Malting Process
Steeping
Germination
H2O
barley
seeds
Steeping - 24-48 hours
green
malt
steeped
barley
air
Kilning
water
spray
H2O
12% H2O
raise
moisture
content
air
45% H2O
malt
Raise grain moisture content
warm air
45% H2O
enzyme
induction,
cell wall
digestion
Wash grain - remove dirt, microbes
4% H2O
drying, avor
development
Bubble air through - aid grain respiration
Soaking in water with air rests
3
What are enzymes?
What are enzymes?
Proteins
A catalyst doesnt cause a reaction to occur.
The reaction would have happened anyway,
but more slowly.
What are enzymes?
Proteins
Catalysts
reactants -->
product
A catalyst makes the reaction happen faster
by reducing the activation energy needed.
reactant --> product
Germination - 4-6 days
Induction of carbohydrate hydrolyzing
enzymes (mainly -amylase, -amylase
and -glucanase)
Induction of protein hydrolyzing enzymes
(proteases).
Modication digestion - of endosperm
cell walls, resulting in softening of the
grain.
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barley kernel (seed)
5
Chitted
Malt
Day
One
Day
Two
Day
Three
Day
Four
Day
Five
barley endosperm cell with starch granules
ungerminated barley with intact
cell walls
Kilning
Reduce moisture to stabilize
germinated barley with degraded
cell walls the starch granules
are exposed
Preserve enzyme activity
Develop color
Develop malty avor
Microbial Sterilization
Wet (autoclave) - requires 121C
Wet vs. Dry Heat
Dry (oven) - requires 400C
The difference is due to energy
transfer in the presence of water
molecules.
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Kilning (24-36 hours)
First stage (free drying) - Moisture
evaporates from grain surface; air
on (entering kiln) 50-60C; moisture ~42%
=> 10-15%.
Second stage - Moisture migrates from
interior to surface; air on 65-75C; moisture
=> ~5%; some enzyme inactivation.
Final stage (curing) - pale lager malt air on
~80C; pale ale malt ~100C; color and
avor formation; malt moisture => 4%.
Malt Color Formation
Caramelization
Sugar-sugar reactions
Melanoidin formation
Reducing sugar - amino acid reactions
Malt Flavor Formation
Roasted, malty & nutty avors, dimethyl
sulde (DMS) precursors.
Many compounds are produced by
breakdown of products of reducing sugaramino acid reactions.
These
include
aldehydes,
oxygencontaining
ring
compounds,
sulfurcontaining compounds, amines, nitrogencontaining ring compounds, and phenolics.
6-row barley
6-row malt
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The Process for Specialty Malts
Steeping
Germination
High Temperature Kilning
Kilning of some specialty malts (e.g.
Munich malt) involves applying more
heat than for a pale malt and heating
earlier.
Roasting
A separate operation, roasting, can be
applied to green malt (germinated
barley), kilned malt or even unmalted
barley.
This results in dark color formation
and special avor formation.
Specialty Malt Production
steeping
germination
roasting
green
malt
kilning
roasting
pale malt
roasting
Its not burned, its blackened.
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Dark malts have reduced or nonexistent enzyme activity, so are
only used as a low percentage of
the
total
malt.
That
also
necessitates lower adjunct levels.
e.g. A bock beer might derive its
very dark color from 10% caramel
malt and 1% black malt.
Other Uses for Malt
Distillers malt
Baking (malt our)
Confectionary
Malted milk
Effects of the Malting Process
Color
Flavor
Texture
Composition
Major Contributions of Malt to Beer
Yeast Nutrition
lipids, amino acids, simple sugars
Flavor
malt avors
Color
colored compounds
Foam
foam-active protein
Processing Aid
husk forms lter bed for lautering
Processing difculties
gel proteins, beta-glucans
Physical instability
haze-active protein, polyphenols
Tasting
Coors Original
Killians Irish Red
Ithaca Nut Brown Ale
Guinness Stout
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